Anchoring assemblies provide points of structural attachment between multiple load-bearing members like beams, or a member to a base material like a cornice to a wall, sheet rock to a beam, or load-bearing metal (steel) beams to hard surfaces (stone or concrete). Certain assemblies also possess terminal segments that protrude from an anchorage surface of the base material into which a screw or hook can be inserted for rigid connection to the anchorage surface in applications involving, for example, the hanging of items like picture frames. These anchoring assemblies comprise a forward or insertion portion that is embedded in the base material or first member and a terminal portion that protrudes from the base material or first member or is embedded in a second member.
There are numerous types of structural anchors known in the art. For example, in light-load applications, the familiar "molley" or "butterfly" requires the drilling of a hole into or through the base material, followed by the insertion of a first portion into the hole, like the flexible expansion retainer of the molley, or through the hole, like the rigid, folded wings of the butterfly which unfold after they pass through the base material into the air space behind it to create a load bearing surface. In these devices, a second portion, typically comprising a screw, is then inserted. Turning of the screw in the flexible retainer of the molley expands the retainer thereby providing frictional resistance against the matrix material of the base material. As the screw is tightened in the butterfly, the expanded wings are pulled against the back of the anchorage surface thereby creating a load supporting surface.
These devices, however, possess a number of drawbacks, including the requirement to first drill a hole prior to use, inability to handle large loads without becoming cumbersome in size, difficulty in use when the base material is hard or dense, and the absolute incapacity to be used in remote locations where the workman cannot reach, touch, size or drill the base material.
With respect to hard or dense base materials, like stone or concrete, or in industrial applications where heavy loads are to be supported, there are generally two groups of anchorage assemblies. The first group consists of expansion bolts or expansion fasteners which, like the light-load molleys and butterflies, are driven into preformed holes. Expansion anchors typically have a main body with a bore and slots at a forward end and a conical plug which is loosely inserted into the bore at the terminal end. When the forward end of the expansion anchor is driven into the hole, the conical plug is also driven beyond the terminal end into the forward end. The pressure of the conical plug against the sides of the forward and terminal ends cause the sides to expand and press into the periphery of the hole. The mechanical resistance of the expansion anchor to pullout is directly proportional to the frictional forces and lateral pressure of the expanded ends against the periphery of the hole. In certain circumstances, the mechanical resistance can be improved by the provision of a sealed connection of an epoxy material at the interface between the anchor and the base material. However, these devices present the same drawbacks as the light-load molleys and butterflies.
The second group of anchoring assemblies used for dense base materials are power-driven, typically involving nail guns, wherein the anchoring assembly is comprised of a durable and rigid material in the shape of a nail, which is forced into the base material either by mechanical or ballistic propulsion. The tip of the nail is usually placed directly against the target area of the base material, so that the kinetic energy created by the gases from the explosion are converted directly into the mechanical work of penetration. However, these devices are unusable for remote targets, that is, where the base material is inaccessible, since they require contact between the base material and the tip of the anchor prior to use.
Other information regarding the present state of the art can be found in certain commercial publications, such as RED HEAD by ITT Philips Drill Division, Rawlplug Co., Drillco Devices and Hilti Fastening Systems. Additional information on fasteners can also be found in ASTM Publications, such as A490, D1761, and on epoxy in C884-83. However, none of these references solve the problem of anchorage to an inaccessible base material, or utilization of kinetic energy from ballistic propulsion to drive an anchoring assembly a distance before reaching a target on the base material. Such an anchoring assembly could assist mountain climbers, firemen, and the like who must scale surfaces, typically without the time or ability to effect anchorage to the surfaces.
It is, therefore, an object of the present invention to provide an anchoring assembly that that can be used in all load applications and for all base materials.
It is yet a further object of the present invention to provide an anchoring assembly that can be fastened to the base material from a distance.
It is still another object of the present invention to provide an anchoring assembly that is deformable by way of a self-contained explosive charge, detonated after penetration into the base material.
It is still a further object of the present invention to provide a ballistically propelled, explosively deformable anchoring assembly that can be launched at the base material at a distance therefrom, to enable anchorage to a remote or inaccessible base material.